DS250DF410: lowest clock freq that can be used as inputs to generate 25.78125 G PRBS patterns.

Hi Ramamurthy,

I would recommend a sub-rate clock of 25.78125 GHz / 32 or higher.

Please see the thread below for more details.

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1289801/ds250df230evm-a-problem-of-prbs-testing-with-ds250df230evm

Thanks,

Drew

HI Drew, Thanks for your response. I am still in the initial design stage for my board and wanted to make sure that I knew the constraints. 

Another question: I am assuming that I can utilize all  the 4 channels on the DS250DF410 to put out PRBS patterns (@25.78125G)simultaneously.  Is my assumption correct?

Thank you very much.

-Gurushankar

I intend to use the retimer solely for PRBS generation and checking @25.78125 G date rates.

I want to get your input on if the following concepts work.

1.

2.

Thank you.

-Gurushankar

Hi Gurushankar,

I believe both of these concepts would work, but I believe option 1 will provide you more flexibility.

One thing I wanted to highlight is that we typically don't recommend enabling more than two PRBS blocks per device.  While it's possible to enable more than two, I believe you will need to add heat sinking to help ensure devices do not overheat.

Thanks,

Drew

Drew,

Thank you very much for your inputs.  The test would very likely need to enable all the 4 lanes simultaneously.  As you have suggested, I will plan for heatsinks. 

Thank you very much, Drew.

-Gurushankar

Thank you very much, Drew.